न वा, प्रकरणभेदात् परोवरीयस्त्वादिवत् ॥ ७ ॥
na vā, prakaraṇabhedāt parovarīyastvādivat || 7 ||
na vā—Rather not; prakaraṇa-bhedāt—on account of difference in subject-matter; parovarīyastvādivat—even as (the meditation on the Udgitha) as the highest and greatest (Brahman) (is different).
7. Rather (there is) no (unity of Vidyas), on account of the difference in subject-matter, even as (the meditation on the Udgitha) as the highest and greatest (i.e. Brahman) (is different from the meditation on the Udgitha as abiding in the eye etc.).
This Sutra refutes the former view and establishes that the two Vidyas, in spite of similarity in many points, are different on account of difference in subject-matter. In the Chhandogya only a part of the Udgitha (hymn), the syllable ‘Om’ is meditated upon as Prana: “Let one meditate on the syllable ‘Om’ (of) the Udgitha” (Chh. 1. 1. 1). But in the Brihadaranyaka the whole Udgitha hymn is meditated upon as Prana. Vide Brih. 1. 8. 2. On account of this difference in the object of meditation the two Vidyas cannot be one. The case is similar to the Upasana on Udgitha enjoined in, “This is indeed the highest and greatest Udgitha” (Chh. 1. 9. 2), which is different from the one enjoined in the Chhandogya 1. 6, where the Udgitha is meditated upon as abiding in the eye and the sun.